The present invention relates to a molding system, and more particularly to a valve assembly which suppresses an initial surge of a fluid material component from a feed assembly.
Many molding systems provide for the mixing of at least two fluid materials to form a harden able or settable mixture which can be discharged into a mold cavity in the formation of an article molded of synthetic resin. One particular mixture includes three components, a catalyst, a matrix polymer and a foaming agent.
The fluid materials are typically fed from a multiple of supplies by a delivery or feed assembly which communicates with a mixing head. All the fluid materials are mixed in the mixing head and discharged into the mold cavity to form the molded article.
All the fluid materials must be efficiently mixed at the mix head to assure a homogeneous composition of the finished material. Since each fluid material typically has a different viscosity, difficulties may arise when the multiple materials are feed to the mix head to provide the proper ratio for the finished material. If the materials are not properly metered upon initial injection, the higher viscosity materials will over populate the ratio. As the catalyst is typically of the highest viscosity, premature curing and an unsightly finished material may result.
Accordingly, it is desirable to provide a valve assembly which assures the proper delivery of each fluid material to the mix head in the proper ratio and from initiation of each cycle of the molding machine.